U.S. patent number 6,733,754 [Application Number 10/389,139] was granted by the patent office on 2004-05-11 for adjuvants for use in vaccines.
This patent grant is currently assigned to Pfizer, Inc., Pfizer Products, Inc.. Invention is credited to Don A. Dearwester, David S. Roberts, Leroy A. Swearingin.
United States Patent |
6,733,754 |
Roberts , et al. |
May 11, 2004 |
Adjuvants for use in vaccines
Abstract
The invention relates to adjuvants that contain a lecithin, an
oil and an amphiphilic surfactant and that are capable of forming a
stable oil-in-water emulsion vaccine so as to minimize local
reactions to the vaccine in the injected animal.
Inventors: |
Roberts; David S.
(Philadelphia, PA), Swearingin; Leroy A. (Waterford, CT),
Dearwester; Don A. (Westerly, RI) |
Assignee: |
Pfizer, Inc. (New York, NY)
Pfizer Products, Inc. (Croton, CT)
|
Family
ID: |
26815550 |
Appl.
No.: |
10/389,139 |
Filed: |
March 13, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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489713 |
Jan 24, 2000 |
6572861 |
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Current U.S.
Class: |
424/184.1;
424/203.1; 424/209.1; 424/234.1; 424/254.1; 424/256.1; 424/278.1;
424/94.1; 424/825; 424/682; 424/492; 424/490; 424/460; 424/458;
424/438; 424/283.1; 554/80; 424/263.1; 424/255.1 |
Current CPC
Class: |
A61K
39/102 (20130101); A61P 31/00 (20180101); A61K
39/39 (20130101); A61K 39/099 (20130101); A61P
37/00 (20180101); A61P 27/16 (20180101); A61P
11/00 (20180101); A61P 11/02 (20180101); A61K
39/0241 (20130101); A61P 31/04 (20180101); A61P
37/04 (20180101); A61K 2039/521 (20130101); A61K
2039/70 (20130101); A61K 2039/552 (20130101); Y10S
424/825 (20130101); A61K 2039/55566 (20130101) |
Current International
Class: |
A61K
39/116 (20060101); A61K 39/39 (20060101); A61K
039/00 () |
Field of
Search: |
;424/203.1,184.1,209.1,210.1,234.1,254.1,255.1,256.1,263.1,278.1,283.1,438,458,460,264.1,253.1,825,236.1,93.3 |
References Cited
[Referenced By]
U.S. Patent Documents
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4789544 |
December 1988 |
Nelson et al. |
5338543 |
August 1994 |
Fitzgerald et al. |
5612042 |
March 1997 |
Jacobs |
5665363 |
September 1997 |
Hansen et al. |
5695769 |
December 1997 |
Frantz et al. |
5888513 |
March 1999 |
Plana Duran et al. |
5968525 |
October 1999 |
Fitzgerald et al. |
6013266 |
January 2000 |
Segers et al. |
6517843 |
February 2003 |
Ellis et al. |
6572861 |
June 2003 |
Roberts et al. |
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Foreign Patent Documents
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2816942 |
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Nov 1978 |
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DE |
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3517805 |
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Nov 1986 |
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DE |
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597852 |
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Dec 1997 |
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EP |
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651609 |
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Nov 1999 |
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EP |
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Primary Examiner: Smith; Lynette R. F.
Assistant Examiner: Portner; Ginny Allen
Attorney, Agent or Firm: Ginsburg; Paul H. Ling; Lorraine B.
Kohn & Associates, PLLC
Parent Case Text
This application is a divisional application of U.S. patent
application Ser. No. 09/489,713, filed Jan. 24, 2000 now U.S. Pat.
No. 6,572,861, which claims the benefit of priority to U.S.
Provisional Application No. 60/117,705, filed Jan. 29, 1999 now
abandoned, and U.S. Provisional Application No. 60/121,760, filed
Feb. 26, 1999 now abandoned, all of which are incorporated herein
by reference.
Claims
What is claimed is:
1. A method for protecting a piglet against atrophic rhinitis by:
a) providing a vaccine comprising Bordetella bronchiseptica cells
inactivated by adding formalin followed by adding 0.4% to 0.8%
volume per volume concentration ("v/v") of glutaraldehyde to the
cells, toxigenic Pasteurella multocida antigens, and a
physiologically acceptable carrier; b) providing a female pig; c)
vaccinating the female pig prior to furrowing and during pregnancy
with an amount of the vaccine effective to provide anti-Bordetella
bronchiseptica antibodies and anti-toxigenic Pasteurella multocida
antibodies in colostrum produced by the female pig; d) bringing the
colostrum into association with a piglet and providing the
colostrum produced by the female pig to the piglet within about 24
hours subsequent to the piglet's birth.
Description
FIELD OF THE INVENTION
The invention relates to immunological adjuvants. In particular,
the invention relates to adjuvants which comprise an oil-in-water
emulsion and a surfactant. Adjuvants of the invention are useful in
a variety of vaccine formulations, including vaccines comprising
bacterial or viral components.
BACKGROUND OF THE INVENTION
The generation of immunity to infectious organisms is a powerful
tool in disease control. Those antigens that induce immunity to
infection are known as immunogens. The protective antibody they
induce may collaborate with other natural defenses to inhibit the
infective process, or they may neutralize harmful products of the
infective organism such as toxins.
An effective means of enhancing the antibody response is the use of
an adjuvant. Thus, an adjuvant is included in a vaccine as an
additive or vehicle to enhance the response to the antigen. An
adjuvant may function by different mechanisms, including (1)
trapping the antigen in the body to cause a slow release, (2)
attracting cells of the immune system to the injection site, (3)
stimulating cells of the immune system to proliferate and to become
activated, and (4) improving antigen dispersion in the recipient's
body.
A number of agents with diverse chemical properties have been used
as adjuvants, including water-in-oil and oil-in-water emulsions,
mineral salts, polynucleotides and natural substances. One
adjuvant, known under the trademark AMPHIGEN.TM., is described in
U.S. Pat. No. 5,084,269. AMPHIGEN.TM. adjuvant consists of de-oiled
lecithin dissolved in an oil, usually light liquid paraffin. In
vaccine preparations AMPHIGEN.TM. is dispersed in an aqueous
solution or suspension of the immunizing antigen as an oil-in-water
emulsion.
Problems were observed when using an AMPHIGEN.TM. adjuvant
according to U.S. Pat. No. 5,084,269, above. For example, the
lecithin in the AMPHIGEN.TM. does not suffice to produce a stable
emulsion of the oil, thus leading to a pool or depot of oil in the
injected tissues. Mineral oil can not be metabolized or removed by
the animal. As a result, the oil becomes a source of severe chronic
inflammation and scarring. Emulsifying the AMPHIGEN.TM. directly in
the antigenic preparation carries the risk of damaging the antigen.
Also, if the desired emulsion fails to form, the valuable antigen
must be discarded.
An adjuvant useful in vaccines for animals, including humans, that
is effective and solves the above problems would therefore be
highly desirable.
SUMMARY OF THE INVENTION
The invention relates to an adjuvant useful for the enhancement of
the immune response of an animal to an antigen. In particular, the
invention relates to an adjuvant that is capable of forming an
oil-in-water emulsion in a vaccine composition. The invention also
relates to an adjuvant that, when used in a vaccine formulation,
causes minimal inflammation and scarring at the vaccination site.
The invention further relates to a vaccine formulation that
contains an adjuvant of the invention. Finally, the invention
relates to a method of using an adjuvant of the invention in a
vaccination.
In one embodiment, the adjuvant of the invention comprises a
lecithin, an oil and an amphiphilic surfactant capable of
emulsifying the adjuvant, for example, a Tween or a Span
surfactant. In another preferred aspect, the surfactant is Tween
80, Tween 85, Span 80 or Span 85.
In another embodiment, the adjuvant of the invention comprises a
lecithin, an oil and two amphiphilic surfactants capable of
emulsifying the adjuvant or a vaccine composition that contains the
adjuvant. In a preferred aspect, one of the two surfactants is
predominantly found in the aqueous phase, for example, Tween 80,
and the other surfactant is predominantly found in the oil phase,
for example, Span 80.
A lecithin is a phosphatide. Crude preparations of lecithin may
include triglycerides. For purposes of the present invention,
"lecithin" encompasses both purified and crude preparations. In a
preferred aspect, the lecithin is de-oiled.
Suitable oils include a mineral oil, for example, DRAKEOL.TM. light
mineral oil.
In a further embodiment, the adjuvant of the invention contains an
aqueous carrier solution, for example, a physiologically acceptable
buffer, water or a saline solution.
In a preferred embodiment, the adjuvant of the invention contains a
lecithin, a mineral oil, two amphiphilic surfactants and an aqueous
carrier solution (e.g., saline).
In another embodiment of the invention, a method to inactivate a
culture of Bordetella bronchiseptica ("B. bronchiseptica") using
formalin and glutaraldehyde is described. In another aspect, a
culture of B. bronchiseptica is provided that was inactivated using
formalin and glutaraldehyde. In yet another aspect, an antigen
composition from a B. bronchiseptica culture is provided that was
inactivated using formalin and glutaraldehyde. In yet another
aspect, a vaccine composition is provided that contains an antigen
composition from a B. bronchiseptica culture that was inactivated
using formalin and glutaraldehyde.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 presents a graph depicting the distribution of droplet sizes
of an emulsion prepared as described below. Liries (a) and (b)
depict that about 94% of the droplets have a diameter of 1 .mu.m or
less.
DETAILED DESCRIPTION OF THE INVENTION
The invention relates to an adjuvant useful for the enhancement of
the immune response to an antigen. In particular, the invention
relates to an oily adjuvant that is capable of emulsifying a
vaccine formulation. Further, the invention relates to an adjuvant
that, when used in a vaccine formulation, is capable of
substantially avoiding the inflammation or scarring at the
injection site, typical of vaccines containing mineral oil.
Adjuvants of the invention comprise a lecithin, an oil and an
amphiphilic surfactant capable of emulsifying the adjuvant or a
vaccine composition that contains the adjuvant.
The invention is based, in part, on the discovery that adding from
about 1.5% v/v (i.e., 1.5% volume per volume concentration obtained
by, e.g., mixing 98.5 volumes of the vaccine comprising the
adjuvant with 1.5 volumes of the amphiphilic surfactant) to 3.5%
v/v of an amphiphilic surfactant to a vaccine containing an
adjuvant as described in U.S. Pat. No. 5,084,269 is effective to
sufficiently emulsify a vaccine composition formulated with such an
adjuvant and to minimize irritation in the injection site of the
vaccinated animal.
In one embodiment, the adjuvant of the invention contains a
lecithin and an oil and an amphiphilic surfactant. In one
embodiment, the adjuvant of the invention contains a lecithin and
an oil and an amphiphilic surfactant capable of emulsifying a
vaccine composition formulated with an adjuvant of the invention.
In another preferred embodiment, two amphiphilic surfactants are
used in an adjuvant of the invention, for example a Tween and a
Span surfactant.
A preferred adjuvant, herein referred to as "No. 1 Adjuvant",
comprises about 2% v/v lecithin, about 18% v/v mineral oil, and
about 8% v/v surfactant (e.g., about 5.6% v/v Tween 80 and about
2.4% v/v Span 80), with the remaining volume being a saline
solution. In a preferred aspect, a vaccine composition is
formulated comprising an antigen at a concentration of about 75%
v/v and an adjuvant, preferably No. 1 Adjuvant, at a concentration
of about 25% v/v of the vaccine composition. All concentrations
provided herein in percentage are indicated in volume per volume
unless the context indicates otherwise.
Surfactants Useful in the Adjuvant of the Invention
Surfactants useful for the adjuvant of the invention are
amphiphilic and acceptable for veterinary or medical use. Whether
or not a particular surfactant is acceptable for medical or
veterinary use can be determined by those of ordinary skill in the
art. A surfactant is amphiphilic if a part of the surfactant
molecule is hydrophobic and a part is hydrophilic. See U.S. Pat.
Nos. 5,690,942; 5,376,369; 4,933,179 and 4,606,918, which describe
surfactants than can be used in the adjuvant of the invention.
Examples of surfactants useful in the adjuvant of the invention
include, but are not limited to, a Tween surfactant and a Span
surfactant. Tween and Span surfactants include, but are not limited
to, monolaureate (Tween 20, Tween 21, Span 20), monopalmitate
(Tween 40, Span 40), monostearate (Tween 60, Tween 61, Span 60),
tristearate (Tween 65, Span 65), monooleate (Tween 80, Tween 81,
Span 80) and trioleate (Tween 85, Span 85). In a preferred
embodiment, Tween 80, Tween 85, Span 80 or Span 85 is used.
It is preferred that a surfactant useful in the adjuvant of the
invention is amphiphilic and has a hydrophilic-lipophilic balance
("HLB") value that is preferably at least about half the sum of the
HLB values of all other components of the adjuvant. More
preferably, the surfactant has an HLB value that is from about half
to about twice the sum of the HLB values of all other components of
the adjuvant. More preferably, the surfactant has an HLB value that
is about the same as the HLB value of all other components of the
adjuvant. HLB values are readily available for surfactants,
lecithins, oils and carrier solutions or, if necessary, can be
determined through routine experimentation. For example, see U.S.
Pat. Nos. 4,504,275 and 4,261,925 and references provided
therein.
Amphiphilic surfactants useful in the adjuvant of the invention
have HLB values from about 2 to about 20, preferably from about 3
to about 17. Methods for determinig the HLB value of particular
surfactants are known in the art. See for example U.S. Pat. Nos.
5,603,951; 4,933,179 and 4,606,918, which describe surfactants
having particular HLB values.
The concentration of a surfactant in a vaccine composition
formulated with the adjuvant of the invention is from about 1.5% to
3.5% v/v, more preferably from about 1.5% to about 3% v/v, more
preferably from about 1.5% to about 2.5%, and most preferably about
2% v/v. When more than one surfactant is used, the sum of the
concentrations of all surfactants used in a vaccine composition
formulated with the adjuvant of the invention is also from about
1.5% to 3.5%, more preferably from about 1.5% to about 3%, more
preferably from about 1.5% to about 2.5%, and most preferably about
2% v/v.
The concentration of a surfactant in the adjuvant of the invention
also depends on the concentration at which the adjuvant is used in
a vaccine composition. For example, a vaccine composition may be
formulated with the adjuvant of the invention so that about 25% of
the volume of the vaccine composition is the adjuvant ("25%
adjuvant") and the remaining about 75% is made up of other
components, for example the antigen composition. In one aspect, the
concentration of the surfactant in a 25% adjuvant is from about 6%
to 14% v/v. More preferably, the surfactant concentration in a 25%
adjuvant is from about 6% to about 12%, more preferably from about
6% to about 10%, and most preferably about 8% v/v.
The concentration of the surfactant in the adjuvant of the
invention is dependent on different factors. For example, the
higher the concentration of oil in the adjuvant the more surfactant
is required to emulsify a vaccine composition formulated with the
adjuvant of the invention. Another factor that is useful to
determine the concentration of a surfactant is the concentration of
a lecithin. The higher the concentration of a lecithin in the
adjuvant, the less surfactant may be required for
emulsification.
When the adjuvant of the invention is used in a vaccine composition
at a concentration of less than 25% v/v, the concentration of the
adjuvant components in the adjuvant has to be increased
accordingly. The aqueous carrier is an exception as the carrier
always comprises the volume that remains unoccupied by all other
components; thus if the concentration of all components except the
carrier increases, the concentration of the carrier in the adjuvant
will decrease and vice versa. For example, when the adjuvant is
used at a concentration of about 12.5% v/v in a vaccine
composition, the concentration of the components in the adjuvant is
about twice the concentration of the components in a 25% adjuvant.
Similarly, when the adjuvant of the invention is used in a vaccine
composition at a concentration that is above 25% v/v, the
concentration of the components in the adjuvant has to be decreased
accordingly, for example when the adjuvant is used at a
concentration of about 50% v/v in a vaccine composition, the
concentration of the components in the adjuvant is about half the
concentration of the components in a 25% adjuvant.
In one embodiment, two amphiphilic surfactants may be used in the
adjuvant of the invention. Preferably, the two surfactants would
include one surfactant that would be more concentrated in an
aqueous phase than in an oil phase of the adjuvant ("hydrophilic
surfactant") and one surfactant that would be more concentrated in
an oil phase of the adjuvant ("lipophilic surfactant"). For
example, Tween 80 would concentrate more in an aqueous phase and
Span 80 would concentrate more in an oil phase. A preferred
hydrophilic surfactant has an HLB value from about 9 to about 20
and a preferred lipophilic surfactant has an HLB value from about 2
to about 9. See U.S. Pat. Nos. 5,603,951; 4,933,179 and 4,606,918,
which describe surfactants with HLB values in both ranges useful
for the adjuvant of the invention.
When two surfactants are used in the adjuvant of the invention, the
total concentration of both surfactants combined in a vaccine
composition formulated with the adjuvant of the invention is from
about 1.5% to 3.5%, more preferably from about 1.5% to about 3%,
more preferably from about 1.5% to about 2.5%, and most preferably
about 2% v/v. The concentration of each of two surfactants used in
the adjuvant of the invention may differ from each other. For
example, when a hydrophilic surfactant and a lipophilic surfactant
are used, for example Tween 80 and Span 80, the concentration of
Tween 80 may be from about 1.2.times. to about 5.times., more
preferably from about 1.5.times. to about 4.times., more preferably
from about 1.8.times. to about 3.times., more preferably from about
2.times. to about 2.5.times. and more preferably about 2.3.times.
as high as the concentration of Span 80, preferably when used in an
adjuvant with a lecithin and an oil concentration as in No. 1
Adjuvant.
The concentration of the hydrophilic surfactant used in the
adjuvant of the invention depends, in part, on the size of the
aqueous phase, and the concentration of the lipophilic surfactant
depends, in part, on the size of the oil phase. In one embodiment,
the adjuvant of the invention that consists of an aqueous phase at
80% v/v and of an oil phase at 20% v/v, may contain a hydrophilic
surfactant at a concentration of up to about 4 times (i.e., 80/20)
the concentration of a lipophilic surfactant, or for example up to
about 2 times.
Non-Surfactant Components of the Adjuvant of the Invention
In addition to an amphiphilic surfactant, the adjuvant of the
invention contains a lecithin and an oil. In another aspect, the
adjuvant of the invention contains an aqueous carrier solution.
Any lecithin known in the art is useful for the adjuvant of the
invention. Lecithin refers to a mixture of phosphatides. When
provided as a crude extract, a lecithin may also contain
triglycerides. Lecithins may be of plant or animal origin. In
addition, lecithins may be synthetically derived. Examples of
lecithins are described in U.S. Pat. Nos. 5,690,942; 5,597,602 and
5,084,269. In a preferred embodiment, the contents of triglycerides
in a lecithin used in the adjuvant of the invention is lowered
compared to its natural source, i.e., the lecithin is de-oiled. A
number of ways are known in the art to de-oil a lecithin, for
example as described in U.S. Pat. No. 5,597,602.
The concentration of a lecithin in a vaccine composition formulated
with the adjuvant of the invention is from about 0.25% to about
12.5% v/v, more preferably from about 0.5% to about 10% v/v, more
preferably from about 0.5% to about 7.5%, more preferably from
about 0.5% to about 5%, more preferably from about 0.5% to about
2.5%, and most preferably from about 0.5% to about 1.25% v/v.
The concentration of a lecithin in a 25% adjuvant is at least about
1% v/v, preferably at least about 2% v/v. In another aspect, the
lecithin concentration in a 25% adjuvant is from about 1% to about
50% v/v, more preferably from about 2% to about 40% v/v, more
preferably from about 2% to about 30% v/v, more preferably from
about 2% to about 20% v/v, more preferably from about 2% to about
10% v/v and most preferably from about 2% to about 5% v/v. The
concentration of a lecithin in the adjuvant of the invention with a
higher or lower concentration is determined as exemplified
above.
The adjuvant of the invention contains an oil, for example an oil
described in U.S. Pat. Nos. 5,814,321; 5,084,269. In a preferred
aspect, the adjuvant of the invention contains a mineral oil, for
example DRAKEOL.TM.. In another aspect, a mixture of oils is used.
The oil may be provided for preparation of the adjuvant of the
invention as pure oil or as a mixture that contains the oil and
another component, for example the lecithin.
The concentration of an oil in a vaccine composition formulated
with the adjuvant of the invention is from about 1% to about 23%
v/v, more preferably from about 1.5% to about 20% v/v, more
preferably from about 2.5% to about 15%, more preferably from about
3.5% to about 10%, more preferably from about 3.5% to about 7.5%,
more preferably from about 4% to about 6% v/v, and most preferably
about 4.5%.
The concentration of an oil in a 25% adjuvant is at least about 5%
v/v, preferably at least about 8% v/v and more preferably at least
about 12% v/v. In another aspect, the oil concentration in a 25%
adjuvant is from about 4% to about 92% v/v, more preferably from
about 6% to about 80% v/v, more preferably from about 10% to about
60% v/v, more preferably from about 14% to about 40% v/v, more
preferably from about 14% to about 30% v/v, more preferably from
about 16% to about 24% and most preferably about 18%. The
concentration of an oil in the adjuvant of the invention with a
higher or lower concentration is determined as exemplified
above.
In another embodiment, an aqueous carrier is used in the adjuvant
of the invention, for example saline (e.g., phosphate-buffered
saline), tris-HCl, citrate-phosphate buffer, Hepes buffers, other
pharmaceutically acceptable buffers known in the art or water. The
pH of the carrier preferably is physiologically acceptable, for
example between 6 and 8, most preferably around 7. The aqueous
carrier used in the adjuvant of the invention preferably takes up
the volume that is not needed for any of the other components.
The adjuvant of the invention is preferably provided at a
concentration that is from about 2.times. to about 10.times. the
concentration after formulation of the adjuvant in a vaccine
composition, more preferably from about 2.times. to about 8.times.,
more preferably from about 3.times. to about 6.times. and most
preferably about 4.times..
Uses of Adjuvants of the Invention
Adjuvants of the invention may be used to enhance the immune
response to an antigen of a vaccine formulation. Adjuvants of the
invention can be used with antigens derived from any bacteria or
from any virus, provided the antigen does not get destroyed or
denatured. Examples of antigens, and not by way of limitation, are
Erysipelothrix rhusiopathiae antigens, Bordetella bronchiseptica
antigens, antigens of toxigenic strains of Pasteurella multocida,
antigens of Eschericia coli strains that cause neonatal diarrhea,
Actinobacillus pleuropneumoniae antigens, Pasteurella haemolytica
antigens, or any combination of the above. Adjuvants of the
invention are also useful in vaccine compositions that contain an
antigen described in U.S. Pat. Nos. 5,616,328 and 5,084,269.
In a preferred embodiment, the adjuvant of the invention is used in
a vaccine formulation containing an antigen obtained from the
liquid phase of an Erysipelothrix rhusiopathiae ("E.
rhusiopathiae") culture. In a preferred aspect, a culture of E.
rhusiopathiae is inactivated by adding formalin (about 0.5% v/v
final concentration) and, after incubation for 24 hours at
37.degree. C., the cells were removed, for example by
centrifugation or filtration. The culture supernatant, in a
preferred embodiment, is concentrated about 10 told and aluminum
hydroxide gel (preferably REHYDRAGEL.TM.) is added to the
concentrated supernatant at a final concentration of about 30% v/v
to stabilize the antigen. In another preferred embodiment,
thimerosal (about 0.01% v/v final concentration) (Dimportex, Spain,
imported through Flavine Inc., Klosters, N.J.) with EDTA (about
0.07% v/v final concentration) are added to the antigens as
preservatives. In another preferred embodiment, a vaccine
composition is formulated comprising the antigen and the adjuvant
of the invention (e.g. No. 1 Adjuvant) with the adjuvant
comprising, for example, about 25% v/v of the vaccine composition.
This preferred E. rhusiopathiae antigen is described in U.S. patent
application Ser. No. 60/117,704, filed Jan. 29, 1999, entitled
"Erysipelothrix rhusiopathiae Antigens and Vaccine Compositions",
which is incorporated herein by reference.
In another preferred embodiment, the adjuvant of the invention is
used in a vaccine composition containing antigens from a B.
bronchiseptica culture that has been inactivated by adding formalin
thereto in log phase, preferably late log phase, followed by the
addition of glutaraldehyde. In addition to killing the bacterial
cells, the purpose of this novel and unique inactivation is to make
nontoxic the endotoxin and exotoxin B. bronchiseptica, while
leaving the antigens of B. bronchiseptica cells effective in
eliciting the desired immune response. Formalin is added to a
concentration in the B. bronchiseptica culture of from about 0.2%
v/v to about 1% v/v, more preferably from about 0.4% v/v to about
0.8% v/v and most preferably about 0.6% V/v. Glutaraldehyde is
added from about 10 minutes to about 40 minutes following the
addition of formalin to the culture, more preferably from about 15
minutes to about 30 minutes and most preferably about 20 minutes.
Glutaraldehyde is added to a concentration in the B. bronchiseptica
culture of from about 0.2% v/v to about 1% v/v, more preferably
from about 0.4% v/v to about 0.8% v/v and most preferably about
0.6% v/v. Prior to adding the glutaraldehyde to the culture, it has
a concentration of from about 10% v/v to about 50% v/v, more
preferably from about 15% v/v to about 35% v/v and most preferably
about 25% v/v. Following the addition of formalin and
glutaraldehyde to the B. bronchiseptica culture, the resulting mix
is incubated under stirring at from about 32.degree. C. to about
42.degree. C., more preferably at from about 35.degree. C. to about
39.degree. C. and most preferably at about 37.degree. C. The mix is
incubated from about 12 hours to about 60 hours, more preferably
from about 24 hours to about 48 hours. All other processing steps
in preparing an antigen composition of the invention from B.
bronchiseptica culture are described in Example 7, infra, and in
U.S. Pat. Nos. 5,019,388 and 4,888,169.
Vaccine Compositions Comprising Adjuvants of the Invention and
their Administration
The adjuvant of the invention may be used in a vaccine formulation
to immunize an animal. In one embodiment, the vaccine formulation
contains the adjuvant of the invention and an antigen. The optimal
ratios of each component in the vaccine formulation may be
determined by techniques well known to those skilled in the
art.
A vaccine formulation may be administered to a subject per se or in
the form of a pharmaceutical or therapeutic composition.
Pharmaceutical compositions comprising the adjuvant of the
invention and an antigen may be manufactured by means of
conventional mixing, dissolving, granulating, dragee-making,
levigating, emulsifying, encapsulating, entrapping or lyophilizing
processes. Pharmaceutical compositions may be formulated in
conventional manner using one or more physiologically acceptable
carriers, diluents, excipients or auxiliaries which facilitate
processing of the antigens of the invention into preparations which
can be used pharmaceutically. Proper formulation is dependent upon
the route of administration chosen. For purposes of this
application, "physiologically acceptable carrier" encompasses
carriers that are acceptable for human or animal use without
relatively harmful side effects (relative to the condition being
treated), as well as diluents, excipients or auxiliaries that are
likewise acceptable.
Systemic formulations include those designed for administration by
injection, e.g. subcutaneous, intradermal, intramuscular or
intraperitoneal injection.
For injection, the vaccine preparations may be formulated in
aqueous solutions, preferably in physiologically compatible buffers
such as Hanks's solution, Ringer's solution, phosphate buffered
saline, or any other physiological saline buffer. The solution may
contain formulatory agents such as suspending, stabilizing and/or
dispersing agents. Alternatively, the proteins may be in powder
form for constitution with a suitable vehicle, e.g., sterile
pyrogen-free water, before use.
Determination of an effective amount of the vaccine formulation for
administration is well within the capabilities of those skilled in
the art, especially in light of the detailed disclosure provided
herein.
An effective dose can be estimated initially from in vitro assays.
For example, a dose can be formulated in animal models to achieve
an induction of an immune response using techniques that are well
known in the art. One having ordinary skill in the art could
readily optimize administration to all animal species based on
results described herein. Dosage amount and interval may be
adjusted individually. For example, when used as a vaccine, the
vaccine formulations of the invention may be administered in about
1 to 3 doses for a 1-36 week period. Preferably, 1 or 2 doses are
administered, at intervals of about 3 weeks to about 4 months, and
booster vaccinations may be given periodically thereafter.
Alternative protocols may be appropriate for individual animals. A
suitable dose is an amount of the vaccine formulation that, when
administered as described above, is capable of raising an immune
response in an immunized animal sufficient to protect the animal
from an infection for at least 4 to 12 months. In general, the
amount of the antigen present in a dose ranges from about 1 pg to
about 100 mg per kg of host, typically from about 10 pg to about 1
mg, and preferably from about 100 pg to about 1 pg. Suitable dose
range will vary with the route of injection and the size of the
patient, but will typically range from about 0.1 mL to about 5
mL.
The invention having been described, the following examples are
offered by way of illustration and not limitation.
EXAMPLE 1
The Use of an Adjuvant that Contains Oil and Lecithin
The following example describes the use of an adjuvant that
contains de-oiled lecithin dissolved in an oil ("oil-lecithin
adjuvant"), usually mineral oil (light liquid paraffin) in
veterinary vaccines. See U.S. Pat. No. 5,084,269, which describes
an oil-lecithin adjuvant. A vaccine preparation using an
oil-lecithin adjuvant is an oil-in-water emulsion.
All percentage concentrations herein are provided in volume per
volume unless indicated otherwise. Percentage values, unless
otherwise indicated, of an oil-lecithin adjuvant refer to the
concentration of a mixture of lecithin (10% of the mixture) and a
carrier oil (DRAKEOL.TM.) (90% of the mixture) in an aqueous
carrier (continuous phase). For example, a 20% oil-lecithin
adjuvant contains 2% v/v lecithin (Central Soya, Fort Wayne, Ind.),
18% v/v DRAKEOL.TM.. 5 (Penreco, Karns City, Pa.) and 80% v/v
saline solution (with the saline content being reduced if other
components, for example surfactants, are added). The percentage
values of an oil-lecithin adjuvant in a vaccine composition, i.e.,
following dilution of the adjuvant solution with the antigen
solution, refer to the concentration of a mixture of lecithin (10%
of mixture) and a carrier oil (DRAKEOL.TM.) (90% of mixture) in the
vaccine preparation which comprises the adjuvant and a solution
containing an antigen, unless the context indicates otherwise. In
all cases where a surfactant was added to an adjuvant composition,
the percentage values for a surfactant concentration refer to the
total concentration of all added surfactants in the adjuvant or the
vaccine preparation, unless the context indicates otherwise.
When an oil-lecithin adjuvant was used as an adjuvant in vaccine
formulations, it was found that it does not emulsify aqueous
preparations without the addition of extra surfactants as the
lecithin in the oil-lecithin adjuvant did not suffice for
emulsification. Therefore, vaccines made using inadequately
dispersed oil-lecithin adjuvant formed a pool or depot of mostly
mineral oil in the tissues at the injection site. This oil can not
be metabolized or removed by the injected animal and so it remains
as a source of severe chronic inflammation and scarring.
It was also determined that adding surfactants to a vaccine
formulation comprising an oil-lecithin adjuvant and an antigen in
order to emulsify the formulation was not an adequate solution.
Problems encountered when adding oil and surfactants to the vaccine
formulation before emulsifying were that the antigen could get
damaged and, if a suitable emulsion was not achieved, that the
formulation would have to be discarded including the valuable
antigen.
Different adjuvant compositions were tested comprising an
oil-lecithin adjuvant in combination with surfactants to emulsify
the vaccine formulations.
EXAMPLE 2
The Use of an Adjuvant Containing a Surfactant at a Low
Concentration
The following example describes the use of an emulsion containing
40% oil-lecithin and 2% of synthetic surfactants, i.e., Tween 80
and Span 80 (Van Water & Rogers, Omaha, Nebr.) in phosphate
buffered saline. This adjuvant was prepared aseptically and
separate from the antigen. The emulsion was added to the antigen
preparation without further emulsification. The synthetic
surfactants helped the oil-lecithin adjuvant to disperse as a
coarse, relatively stable emulsion. The adjuvant emulsion was added
to the aqueous antigenic preparation at the rate of one in eight,
decreasing the oil-lecithin adjuvant content from 40% to 5%, and
the surfactants from a combined 2% to 0.25%.
The adjuvant was used in several vaccines. It was found that
because the emulsion is coarse and not very stable, the oil
droplets tend to coalesce and to separate as a permanent,
irritating depot of oil in the injected tissues. Another problem
observed with this adjuvant was that it aggregates with Al gel. A
number of vaccines contain Al gel for a number of purposes like,
for example, as an adjuvant or to stabilize an antigen or to bind
endotoxin. The oil-lecithin adjuvant carries a negative charge
which causes it to bind to the positively charged Al gel to form
coarse aggregates. These aggregates are unsightly, difficult to
pass through a hypodermic needle, and very irritating to the
injected tissues.
EXAMPLE 3
The Use of an Adjuvant Containing a Surfactant at a High
Concentration
An oil-lecithin adjuvant (5% v/v) was emulsified in the antigenic
preparation with the help of Tween 80 and Span 80 surfactants, as
above, but at a total surfactant concentration of 8% in the vaccine
composition. The emulsion was very fine and stable. It had almost
the clarity of a solution and it did not cream on standing. Under
the microscope, with maximum magnification (resolution 0.2 micron),
most droplets were too small to be visible. Thus, it was a
microemulsion. This adjuvant, when used in a vaccine formulation,
was found to be virtually free of injection-site reactivity and,
when Al gel was added, there was no detectable aggregation of oil
and gel. As a result of its high surfactant content, this adjuvant
is easy to emulsify, attractive in appearance, stable, unreactive
with Al gel, and virtually free of irritating effects at the site
of vaccination. Despite these advantages, however, this emulsion
had slightly lower adjuvant potency compared to the coarse version
made with surfactants at a low concentration.
EXAMPLE 4
The Use of an Adjuvant Containing a Surfactant at a Medium
Concentration
An attempt was made to find an adjuvant emulsion that is acceptably
smooth and fully potent as an adjuvant. A 20% oil-lecithin adjuvant
was used in these experiments as it was found that a 20%
oil-lecithin adjuvant emulsion is easier to make than a 40%
oil-lecithin adjuvant emulsion. Its addition to vaccines at a rate
of one in four, to make a final oil concentration of 5%, would
leave 75% of the dose volume for antigens. Preliminary experiments
showed that a smooth submicron emulsion (most droplets had a
diameter of less than one micron, see FIG. 1) could be prepared
with 20% oil and 16% of Tween 80 and Span 80 surfactants.
Two emulsions were prepared for the assays. One contained a 20%
oil-lecithin adjuvant and 16% of Tween 80 and Span 80 surfactants.
Diluting it one in four resulted in an emulsion comprising 5%
oil-lecithin adjuvant and 4% surfactants in the vaccine
preparation. The other emulsion was prepared with a 40%
oil-lecithin adjuvant and 2% of Tween 80 and Span 80 surfactants.
Diluting it one in eight gave an emulsion with 5% oil-lecithin
adjuvant and 0.25% surfactants.
Al gel (REHYDRAGEL.TM. obtained from Reheis, Berkeley Heights,
N.J.) was added to a concentration of 10% to samples of each
emulsion. In the emulsion with 0.25% surfactants the oil and Al gel
aggregated and separated to form a thick layer at the top of the
liquid column (creaming). In the emulsion with 4% surfactants, by
contrast, there was no aggregation or creaming. With 4%
surfactants, the Al gel sedimented at the bottom of the tube
leaving the oil droplets dispersed in the supernatant fluid.
EXAMPLE 5
Swelling of Injection Sites when Using an Adjuvant Containing a
Surfactant at a Medium Concentration
Vaccine preparations were tested in pigs to determine whether
swelling of the injection site occurred when an adjuvant with a
medium concentration of surfactant was used. Vaccine preparations
that contain a 5% oil-lecithin adjuvant and either 0.25% or 4%
surfactants caused no swelling in pigs at the injection site. When
Al gel was added to the vaccine preparation at a concentration of
10%, the preparation with 0.25% surfactants caused severe injection
site swellings whereas the one with 4% surfactants resulted in
almost no swelling.
Experiments were carried out to determine the range of surfactant
concentrations that are effective in preventing aggregation with Al
gel and swelling of the injection site. When using a 1.5%
surfactant concentration in the vaccine, slight aggregation of oil
and Al gel was observed. The aggregation was much heavier at lower
surfactant concentrations. At 2% and 4% surfactant concentrations,
there was no aggregation. The swelling induced in pigs by vaccine
preparations containing 0.5% or less surfactants were larger at 2
and 4 weeks after vaccination than those induced by preparations
with 1% or more surfactants. By 6 weeks after vaccination, it was
evident that 1.5% surfactants was the minimum needed to avoid
chronic swellings.
EXAMPLE 6
Adjuvants with Useful In Vitro and In Vivo Properties
Assays were carried out to find an adjuvant that does not react
with Al gel and does not lead to reactivity in the animal following
vaccination. A 20% oil-lecithin adjuvant that contains 8%
surfactants, resulting in a vaccination preparation with 5%
oil-lecithin adjuvant and 2% surfactant, was determined to be
sufficient to avoid both in vitro reactivity with Al gel and
irritation of the tissues at the vaccination site. Evidence of a
relationship between surfactant concentration and adjuvant power
was much less clear. There were occasional indications that 4%
surfactants in the vaccine was excessive, e.g. in the induction of
agglutinin to E. coli K99, and neutralizing antitoxin to the toxin
of P. multocida Type D.
Thus, it was determined that the optimal concentration of
surfactants was 8% in a 20% oil-lecithin adjuvant, resulting in 2%
surfactants in the vaccine composition. This provided for
reasonably easy emulsification and for good stability in cold
storage. In vaccines with 5% oil-lecithin adjuvant, 2% surfactants
was ideal for both adjuvant power and freedom from irritancy in the
injected tissues.
The droplet size in the submicron emulsion of a 20% oil-lecithin
adjuvant with 8% surfactants was determined. The 8% surfactant
consisted of 5.6% Tween 80 in the aqueous phase and 2.4% Span 80 in
the oil phase. About 94% of all droplets were less than 1 micron in
diameter, see FIG. 1.
A stock of 100 mL of a 20% oil-lecithin adjuvant with 8%
surfactants was made from 200 mL filter-sterilized lecithin-oil
solution (10% lecithin in DRAKEOL.TM. mineral oil), autoclaved
Tween 80 (56 mL) and Span 80 (24 mL), and phosphate buffered saline
(720 mL) (Dulbecco PBS). The lecithin-oil solution and Span 80 were
combined and mixed in a sterile tank for at least 1 hour at room
temperature until emulsification was complete. The saline and Tween
80 were combined and mixed in a sterile tank for at least 1 hour at
room temperature. The oil mixture was emulsified in the aqueous
mixture using an emulsifier. Emulsification was continued by
recirculation until all of the adjuvant was added into the saline.
The emulsion was then passed twice through a homogenizer at room
temperature. The adjuvant was stored at 2 to 80 C.
EXAMPLE 7
Atrophic Rhinitis Vaccine Using an Adjuvant Containing a Surfactant
at a Medium Concentration
The adjuvant as described in Example 4 with a medium concentration
of surfactants was used in an Atrophic Rhinitis Vaccine which
contained antigens of Bordetella bronchiseptica and toxigenic
Pasteurella multocida. A Bordetella bronchiseptica-Pasteurella
multocida Bacterin-Toxoid vaccine was made from B. bronchiseptica
cells and the toxoid of P. multocida.
B. bronchiseptica cells, strain 2-9 NADL, were prepared as
described in U.S. Pat. Nos. 5,019,388 and 4,888,169 except that at
the end of the growth cycle, cultures were continuously mixed and
formalin solution was added to a final concentration of 0.6%.
Within 20 minutes after the addition of formalin, a 25%
glutaraldehyde solution was added to a final concentration of 0.6%.
The culture was stirred for 24 to 48 hours at 37+2.degree. C. to
complete inactivation and detoxification. (See Table 1). Then, the
culture fluids were cooled to 15.degree. C. or less for processing.
Inactivated cultures not processed immediately were stored at 2 to
8.degree. C. for up to 14 days. Following inactivation, the
bacteria were separated from the culture fluid by centrifugation.
The supernatant was discarded and the cells were resuspended in
phosphate-buffered saline at approximately one tenth of the
original volume. The concentrated suspension was stored at 2 to
8.degree. C. The treatment of B. bronchiseptica with two aldehydes
inactivates both the endotoxin and the exotoxin, obviating other
treatments for safety.
The toxoid of P. multocida was prepared in two different forms as
described in U.S. Pat. Nos. 5,536,496 and 5,695,769. In one form,
the toxin is toxoided within the bacterial cells by the addition of
formaldehyde to the culture; the toxoid stays inside the cells. In
the other form, the live cells are mechanically disrupted and the
toxin extracted. The toxin is toxoided by exposure to a high pH, as
described in U.S. Pat. No. 5,536,496. Both forms of the toxoid are
treated with Al gel to control free endotoxin by a patented
process, as described in U.S. Pat. No. 5,616,328. (See Table 1). A
synergy between the two forms of pasteurella toxoid results in
antitoxin responses far exceeding the sum of the responses to each
form when used alone as described in U.S. Pat. No. 5,695,769.
TABLE 1 Treatment of cells during preparation of the Bordetella
Bronchiseptica-Pasteurella Multocida Bacterin-Toxoid vaccine Target
Temp. Time Antigen Inactivant Concentration Range (Min/Max) B.
bronchiseptica Formalin 0.6% 37 .+-. 2.degree. C. 24-48 hours
Glutaraldehyde 0.6% P. multocida cell-bound Formalin 0.4% 37 .+-.
2.degree. C. 5 days toxoid P. multocida cell-free 5N NaOH pH 10
.+-. 0.2 15 .+-. 2.degree. C. 1 to 6 hours toxoid
The adjuvant described in Example 4 was added to result in
concentrations of 5% oil-lecithin adjuvant and 2% surfactants in
the vaccine formulation.
A trial to determine the minimum immunizing dose of the atrophic
rhinitis vaccine demonstrated the adjuvant properties of the
oil-lecithin adjuvant with a medium concentration of surfactants.
Pregnant sows were vaccinated with two 2 mL doses at an interval of
4 weeks. They farrowed about 2 weeks after the second dose. At one
month of age, their pigs were subjected to a severe challenge,
consisting of virulent B. Bronchiseptica and P. Multocida cultures
given intranasally in sequence. The pigs born to 7 sows vaccinated
only with a placebo developed severe atrophic rhinitis. The litters
of all 7 sows given vaccine containing a full dose of the antigens
were strongly protected by the maternal antibody still in
circulation. Sows given vaccines containing 1/2 or 1/8 dose of
antigens did not provide their litters with satisfactory
protection.
EXAMPLE 8
Erysipelas Vaccine Using an Adjuvant Containing a Surfactant at a
Medium Concentration
The adjuvant described in Example 4 with a medium concentration of
surfactants was used in an erysipelas vaccine which contained E.
rhusiopathiae antigens. The antigens for use in a vaccine were made
from E. rhusiopathiae cultures inactivated with 0.5% formalin for
at least 24 hours. The inactivated cultures were clarified by
centrifuging, and concentrated roughly tenfold by molecular
filtration. The concentrates were stabilized by adding Al gel,
i.e., REHYDRAGEL.TM., to a concentration of 30%. The preadsorbed
concentrates were included in the vaccine in an amount such that
each 2 mL dose contained at least 3.2 opacity units (OU) as
calculated from the optical density (OD) of the culture at
inactivation. (The OD is multiplied by the final concentration
factor to give a value in OU per mL.)
An Erysipelas vaccination was carried out to determine the efficacy
of a vaccine containing the oil-lecithin adjuvant with a medium
concentration of surfactants. The adjuvant as described in Example
4 was added at a final concentration of 25% v/v, giving a final
lecithin oil concentration of 5%. Thimerosal (0.01% w/v), with EDTA
(0.07% w/v), was added as preservative.
Vaccines made according to this formula were tested twice for
efficacy in pigs. In each case pigs were vaccinated with two 2 mL
doses given intramuscularly (IM) one dose at about 3 weeks
(weaning) and the second dose 3 weeks later. Controls received
phosphate-buffered saline as a placebo. Immunity was challenged by
the IM injection of virulent E. Rhusiopathiae at about 9 weeks of
age in one study and 6 months of age in the other. As shown in
Table 2, protection due to vaccination was 100% at 9 weeks and 75%
at 6 months (i.e., slaughter age). These results indicated that the
vaccine provides satisfactory protection against Erysipelas
throughout the normal feeding period.
The vaccine used in the group challenged at 9 weeks was already 12
months old. The result confirms that the protective antigen was
successfully stabilized.
TABLE 2 Protection of pigs against Erysipelas Controls Vaccinates
Age at Challenge (Protected/Challenged) (Protected/Challenged) 9
weeks 0/10 19/19 6 months 0/10 15/20 Note: In the vaccinated group
challenged at 9 weeks, the 20th pig was excluded. A very fractious
animal, it struggled so violently when handled that its temperature
at rest could not be determined. Following challenge this pig
remained completely healthy.
The invention is not to be limited in scope by the exemplified
embodiments which are intended as illustrations of single aspects
of the invention, and any adjuvants which are functionally
equivalent are within the scope of the invention. Indeed, various
modifications of the invention in addition to those described
herein will become apparent to those skilled in the art from the
foregoing description and accompanying drawings. Such modifications
are intended to fall within the scope of the appended claims.
All publications cited herein are incorporated by reference in
their entirety.
* * * * *